A celestial body that orbits a star, possesses enough mass to maintain a nearly spherical shape due to its own gravity, and has cleared its orbital neighborhood of other debris; in our solar system, these include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, excluding dwarf planets and asteroids.
A term that refers to a relatively large astronomical object that orbits a star, specifically one that meets the criteria established by the International Astronomical Union in 2006, which redefined our solar system's planets from nine to eight by excluding Pluto.
A person whose abilities or capabilities may not be widely recognized, yet is perceived as potentially influential or promising in a particular field or context, often used figuratively to describe someone who may unexpectedly succeed or rise to prominence.
Example:
他の惑星には生命が存在するのですか。
A small celestial body that orbits the Sun, primarily found in the region between the orbits of Mars and Jupiter, typically with a diameter of less than 800 kilometers and possibly numbering in the tens of thousands.
A type of minor planet that consists of numerous small objects that circle the Sun, mainly located in the asteroid belt, with most having a radius of just a few kilometers.
A small astronomical object characterized by its rocky composition, existing in the solar system with established orbits, many of which remain undetermined in terms of their trajectory.
A type of planet in the solar system that orbits the sun within the trajectory of Earth's orbit, specifically referring to Mercury and Venus.
Planets located closer to the sun than Earth, characterized by their smaller size and rocky composition compared to outer planets.
The classification of celestial bodies that includes Mercury and Venus, which possess orbits that are situated between the sun and Earth ’s orbit.
A planet that orbits the Sun at a distance greater than that of Earth, specifically including Mars, Jupiter, Saturn, Uranus, and Neptune.
Any planetary body within the solar system that resides beyond the orbit of Earth, contrasting with inner planets like Mercury and Venus.
Celestial bodies that are part of our solar system, marked by their position outside of Earth's orbital path, distinguished by their larger sizes and gaseous or icy compositions.
天体としての惑星を調査し、情報を収集する科学的な活動。
宇宙に存在する惑星の環境や構造を理解するための探査ミッションや活動。
人類が惑星に関する知識を深めるために行う、宇宙技術を用いた探検のプロセス。